POS0848 HEALTHCARE RESOURCE UTILIZATION AND COST BURDEN OF DERMATOMYOSITIS
Authors: A. Bensimon, K. Chen, A. Noman, R. Taiji, E. Yim, V. Sikirica, R. Aggarwal
Journal: Annals of the Rheumatic Diseases (2022)

Background Dermatomyositis (DM) is a rare chronic systemic autoimmune disease characterized by muscle weakness and skin rashes. DM is also frequently associated with other clinical manifestations including interstitial lung disease, calcinosis, dysphagia, cardiac involvement, and malignancy. With few approved treatment options, DM has high morbidity and mortality. Limited information is available on the economic impact imposed by DM on the healthcare system. Objectives To estimate the economic burden associated with DM in a prevalence cohort, including healthcare resource utilization and costs from both the health insurance plan and patient perspectives. Methods A retrospective cohort study was conducted using a large, integrated administrative database of employer-sponsored commercial and public health plans in the United States (PharMetrics Plus, Jan 2014 - June 2020). Patients (age ≥18 years) were selected if they were diagnosed with dermatomyositis (≥1 inpatient claim or ≥2 outpatient claims ≥30 days apart with International Classification of Diseases, 10th Revision, Clinical Modification: M33.0x, M33.1x, or M33.9x) and continuously enrolled in the health plan during the 6 months before (baseline) and 1 year after (follow-up) a randomly selected DM diagnosis date (index date). Patients were matched 1:3 to a control group without DM or related myositis conditions based on birth year, gender, census region, insurance plan type, and index year. Healthcare resource use (HCRU) and costs over the 1-year follow-up period were compared between patients with DM versus matched controls to assess the incremental economic burden of DM. Statistical comparisons were conducted using generalized estimating equation models with binomial, negative binomial, or Tweedie distributions for binary, count, and cost outcomes, respectively. The models used robustly clustered standard errors to account for correlation between the matched samples. Results Patients with DM (N=3,207) and matched controls (N=9,621) were 49.4 years old on average and 76.8% were female. HCRU was significantly higher among patients with DM than controls in terms of outpatient, inpatient, emergency room, and other medical visits (all p&lt;0.001; Table 1). Medical service and pharmacy costs to the plan were also significantly higher for patients with DM (p&lt;0.001 vs. controls for all cost categories; Figure 1). Total annual costs to the healthcare plan were 5.4-fold higher among patients with DM (mean ± standard deviation: $39,508 ± 83,093) relative to controls without DM ($7,349 ± 32,816) (Δ=$32,159; p&lt;0.001). Outpatient visit costs ($28,131) comprised 71.2% of the total for patients with DM; costs of outpatient-administered DM-related treatments ($15,855) accounted for the majority of outpatient visit costs. Patients with DM incurred 2-fold higher out-of-pocket costs (coinsurance, copayments, or deductibles) than controls ($4,803 ± 13,181 vs. $2,456 ± 10,708; Δ=$2,346; p&lt;0.001). Table 1. Annual resource use in patients with DM vs. controls Patients with DM N = 3,207 Controls N = 9,621 IRR or OR 95% confidence interval P-value Inpatient admissions, mean ± SD 0.2 ± 0.7 0.1 ± 0.4 3.1 (2.6 - 3.7) &lt; 0.001 Any inpatient admission, % 12.1% 4.9% 2.7 (2.3 - 3.1) &lt; 0.001 Outpatient visits, mean ± SD 27.7 ± 31.7 10.8 ± 18.9 2.6 (2.4 - 2.7) &lt; 0.001 Emergency room visits, mean ± SD 0.7 ± 1.6 0.4 ± 1.2 1.8 (1.6 - 2.0) &lt; 0.001 Any emergency room visit, % 30.4% 20.7% 1.7 (1.5 - 1.8) &lt; 0.001 Other visits, mean ± SD 0.3 ± 0.8 0.2 ± 0.7 1.8 (1.6 - 2.1) &lt; 0.001 Any other visit, % 20.0% 11.2% 2.0 (1.8 - 2.2) &lt; 0.001 IRR: incidence rate ratio; OP, outpatient; OR: odds ratio, SD: standard deviation. Notes: IRRs are reported for count outcomes; ORs are reported for binary outcomes. Other visits include durable medical equipment and dental or vision care. Conclusion DM is associated with substantial HCRU and costs per patient, with average incremental costs of $32,159 to the health plan and $2,346 to the patient annually as compared to controls. This study is among the first to document the clinical burden leading to high economic impacts of DM. Acknowledgements Funding for this study was provided by Pfizer Inc. Disclosure of Interests Arielle Bensimon Consultant of: Pfizer, as an employee of Analysis Group, Kristina Chen Employee of: Pfizer, Ahmed Noman Consultant of: Pfizer, as an employee of Analysis Group, Riley Taiji Consultant of: Pfizer, as an employee of Analysis Group at the time that this study was conducted, Erica Yim Consultant of: Pfizer, as an employee of Analysis Group, Vanja Sikirica Shareholder of: Pfizer, which manufactures medications approved for use in Rheumatology., Employee of: Pfizer at the time of this work and a current employee of Moderna., Rohit Aggarwal Consultant of: Abbvie, Alexion, AstraZeneca, Pfizer, Octapharma, Csl Behring, BMS, Argenx, Corbus, EMD, Janssen, Kezar, Kyverna, Roivant, Q32, Corbus, EMD Serono, Jubliant, Scipher, Boehringer Ingelheim and Mallinckrodt, Grant/research support from: Pfizer, BMS, Q32, EMD Serono, Mallinckrodt, Genentech, and Boehringer Ingelheim